A bellows 1004 is a component used in a gate valve (GV) assembly 1002 of a sputtering machine 1000 (see FIGS. 10a, 10b, 10c). In the sputtering machine, the bellows moves together with a GV actuator shaft in both forward and reverse directions in accordance with vacuum pressure. The sputtering machine is often used in the manufacturing of media disks used for magnetic recording. The sputtering machine may have a number of process chambers (e.g., about twenty to twenty-four chambers) where carrier holders (for holding disks or substrates) are transferred from one chamber to another chamber to enable the disks to be sputtered. Each carrier holder will go in and out of each chamber and generally stop for a few seconds in each chamber during the process flow to complete one cycle. When a carrier holder stops in a chamber, the GV assemblies close both ends of the chamber. When both ends of the chamber are closed, the environment inside the chamber may be kept in a vacuum condition which allows the sputtering process to begin. In each of the chambers, there may be a cathode that will sputter the target material onto the disk.
The GV assembly is used to provide separation between adjacent process chambers of a sputtering machine to ensure that the respective sputtering processes for each individual chamber remain separate. This is achieved when the GV assembly extends its actuator shaft to close the opening between the chambers and compress the bellows. The bellows is an elastic component (e.g., an elastic metallic vessel) that can be compressed or extended under vacuum pressure. When the vacuum pressure is released, the compressed bellows will return to its original uncompressed shape. In the sputtering machine, the bellows protects the inside environment of the process chamber from being exposed to the outside environment (e.g., atmosphere environment). If the bellows is found to have a leak, the bellows needs to be replaced. However, detecting a leak in the bellows of a sputter machine can involve complicated and time consuming test processes.